<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
                    "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
  <script src="http://code.jquery.com/jquery-latest.js"></script>
  
  <script>
  $(document).ready(function(){
    $("div > p").css("border", "1px solid gray");
  });
  </script>
  
</head>
<body>
  <p>one</p> <div><p>two</p></div> <p>three</p>
</body>
</html>

